1. Field of the Invention
The invention relates to an electromagnetic deflection unit for a picture tube comprising deflection coils which are carried by a conical coil holder of synthetic material, and a conical ring of soft magnetic material cooperating with the coils, the coil holder having a flange at its wide end and the conical ring being secured at its wide end to the flange of the coil holder. The invention further relates to a picture tube provided with such a deflection unit.
2. Description of the Prior Art
Such a deflection unit is known from "Funkschau" 25, 1242-6 (1975).
For a correct operation of the deflection unit, it is necessary that the conical ring of soft magnetic material, the so-called yoke ring, is aligned with respect to the coils in directions at right angles to the longitudinal direction of the conical coil holder. In the known deflection unit, the conical ring is adhered in the correct position to the flange of the coil holder by means of a comparatively rapidly curing glue and is then fixed in that position by means of a curing mass of synthetic material. For the known deflection unit, not only a large quantity of mass of synthetic material, but also a long period of time is required for causing this mass to be cured. These factors have a great influence on the cost of the unit.